Nobody who really knows is talking about what RockMelt's browser will actually do, but I have an idea: It will be an applications platform more than merely a way to surf the web. And it may even become an operating system for Facebook users.

How do I know this? Well, there are the hints of a linkage to Facebook, but there is also the larger trend toward cloud-based applications, some of might benefit from additional browser features. There is also the announcement of Google Chrome OS, which blurs the line between browser and operating system. And don't forget the battle between Google Docs and Microsoft Office over Web-based productivity suites.

My sense is that Chrome OS will be aimed more at business applications, while Microsoft will move toward "browser-as-operating-system" as slowly as the market allows. I am not sure what happens to Firefox in this scenario, but I expect it to learn to play as an applications platform, too. It already supports a large number of add-ons.

RockMelt could become a browser that supports new social networking applications within the browser rather than online. It could, for example, include features like StumbleUpon's URL sharing and FriendFeed's aggregation within the browser. Or maybe it will offer an API that allows social networks to access RockMelt-only functionality.

My crystal ball is cloudy on the specifics, but it seems obvious there is no reason to invest in a new browser unless it can do something special that also has the ability to generate revenue. Paid applications could qualify as special and benefit from custom browser support, too.

Since Microsoft first entered the browser business, there has been a concern that Redmond would link its browser, applications, and development tools in such a way as to lockout competitors. While Microsoft has not done that, concern about bundling the OS with a browser continues to make legal news in Europe.

Microsoft is in a difficult position here, but as competitors bring out products that link browsers and applications more closely, Microsoft will have legal cover to do so itself.

A key question is how proprietary this will all become. Will Facebook offer features that work best, maybe only work, with the RockMelt browser? Will Microsoft really leverage all its assets to maintain its hold over corporate applications and dev tools?

I noticed over the weekend that when I downloaded Google Earth onto a new PC that the Chrome browser was also installed--whether I wanted it or not. There was a time when such a tie-in would be a scandal, at least if Microsoft did it, but Google seems immune.

I would like to be more specific. I know what I am seeing--a move toward using the browser more like an operating system--but I don't yet understand how it will play out. However, the signs are there and they are worth discussing.